Fix swapFile vhd conflict with distro data vhd issue #14045

[wangxin12]

Summary of the Pull Request

Detect and fail with a clear error message when .wslconfig's swapFile setting points to a distribution's data VHD, preventing silent data corruption.

PR Checklist

• Closes: Link to issue 无法启动分发。错误代码： 16，失败步骤： 2 错误代码: Wsl/Service/CreateInstance/E_FAIL #14045
• Communication: I've discussed this with core contributors already. If work hasn't been agreed, this work might be rejected
• Tests: Added/updated if needed and all pass
• Localization: All end user facing strings can be localized
• Dev docs: Added/updated if needed
• Documentation updated: If checked, please file a pull request on our docs repo and link it here: #xxx

Detailed Description of the Pull Request / Additional comments

Add a validation check in LxssUserSessionImpl::_CreateVm() (after config is loaded, before WslCoreVm::Create) that enumerates all registered distributions and compares their VHD paths against the resolved swap file path. If a match is found, throw with a localized user-facing error message.

Validation Steps Performed

.wslconfig

[wsl2]
swapFile=C:\\Users\\xiwang4\\AppData\\Local\\wsl\\{810478d7-db70-441e-ab8d-5652658b748a}\\ext4.vhdx

Unit test

[Copilot]

Pull request overview

Adds a safety check in the Windows WSL service to prevent .wslconfig’s swapFile from pointing at a distribution’s data VHD, returning a dedicated HRESULT and localized user-facing message to avoid silent filesystem corruption.

Changes:

• Add swapFile-vs-distro-VHD conflict detection during VM creation (LxssUserSessionImpl::_CreateVm).
• Introduce new error code WSL_E_SWAP_FILE_CONFLICTS_WITH_DISTRO and wire it into error-to-string mapping.
• Add localized string and a new Windows unit test covering the conflict scenario.

Reviewed changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
test/windows/UnitTests.cpp	Adds a unit test asserting WSL fails with the new error when swapFile targets a distro VHD.
src/windows/service/inc/wslservice.idl	Defines new HRESULT WSL_E_SWAP_FILE_CONFLICTS_WITH_DISTRO.
src/windows/service/exe/LxssUserSession.cpp	Implements swapFile conflict validation during VM creation.
src/windows/common/wslutil.cpp	Adds the new error to common HRESULT-to-name mapping used in output.
localization/strings/en-US/Resources.resw	Adds localized user-facing error message for the new validation.

[benhillis]

Honestly probably a better solution is just to enforce that we need to create the swap .vhd ourselves. Might be a minor UX difference, but I think that's fine.

[wangxin12]

Honestly probably a better solution is just to enforce that we need to create the swap .vhd ourselves. Might be a minor UX difference, but I think that's fine.

@benhillis so we can just disable the "swapFile" option in .wslconfig? I'd like to confirm this solution with you before I make the change.